perf-eh_elf/util/strbuf.h

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Merge tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull AFS fixes from David Howells: "Here's a set of patches that fix a number of bugs in the in-kernel AFS client, including: - Fix directory locking to not use individual page locks for directory reading/scanning but rather to use a semaphore on the afs_vnode struct as the directory contents must be read in a single blob and data from different reads must not be mixed as the entire contents may be shuffled about between reads. - Fix address list parsing to handle port specifiers correctly. - Only give up callback records on a server if we actually talked to that server (we might not be able to access a server). - Fix some callback handling bugs, including refcounting, whole-volume callbacks and when callbacks actually get broken in response to a CB.CallBack op. - Fix some server/address rotation bugs, including giving up if we can't probe a server; giving up if a server says it doesn't have a volume, but there are more servers to try. - Fix the decoding of fetched statuses to be OpenAFS compatible. - Fix the handling of server lookups in Cache Manager ops (such as CB.InitCallBackState3) to use a UUID if possible and to handle no server being found. - Fix a bug in server lookup where not all addresses are compared. - Fix the non-encryption of calls that prevents some servers from being accessed (this also requires an AF_RXRPC patch that has already gone in through the net tree). There's also a patch that adds tracepoints to log Cache Manager ops that don't find a matching server, either by UUID or by address" * tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Fix the non-encryption of calls afs: Fix CB.CallBack handling afs: Fix whole-volume callback handling afs: Fix afs_find_server search loop afs: Fix the handling of an unfound server in CM operations afs: Add a tracepoint to record callbacks from unlisted servers afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID afs: Fix VNOVOL handling in address rotation afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility afs: Fix server rotation's handling of fileserver probe failure afs: Fix refcounting in callback registration afs: Fix giving up callbacks on server destruction afs: Fix address list parsing afs: Fix directory page locking
2018-05-15 19:48:36 +02:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_STRBUF_H
#define __PERF_STRBUF_H
/*
* Strbuf's can be use in many ways: as a byte array, or to store arbitrary
* long, overflow safe strings.
*
* Strbufs has some invariants that are very important to keep in mind:
*
* 1. the ->buf member is always malloc-ed, hence strbuf's can be used to
* build complex strings/buffers whose final size isn't easily known.
*
* It is NOT legal to copy the ->buf pointer away.
* `strbuf_detach' is the operation that detachs a buffer from its shell
* while keeping the shell valid wrt its invariants.
*
* 2. the ->buf member is a byte array that has at least ->len + 1 bytes
* allocated. The extra byte is used to store a '\0', allowing the ->buf
* member to be a valid C-string. Every strbuf function ensure this
* invariant is preserved.
*
* Note that it is OK to "play" with the buffer directly if you work it
* that way:
*
* strbuf_grow(sb, SOME_SIZE);
* ... Here, the memory array starting at sb->buf, and of length
* ... strbuf_avail(sb) is all yours, and you are sure that
* ... strbuf_avail(sb) is at least SOME_SIZE.
* strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE);
*
* Of course, SOME_OTHER_SIZE must be smaller or equal to strbuf_avail(sb).
*
* Doing so is safe, though if it has to be done in many places, adding the
* missing API to the strbuf module is the way to go.
*
* XXX: do _not_ assume that the area that is yours is of size ->alloc - 1
* even if it's true in the current implementation. Alloc is somehow a
* "private" member that should not be messed with.
*/
#include <assert.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <linux/compiler.h>
#include <sys/types.h>
extern char strbuf_slopbuf[];
struct strbuf {
size_t alloc;
size_t len;
char *buf;
};
#define STRBUF_INIT { 0, 0, strbuf_slopbuf }
/*----- strbuf life cycle -----*/
int strbuf_init(struct strbuf *buf, ssize_t hint);
void strbuf_release(struct strbuf *buf);
char *strbuf_detach(struct strbuf *buf, size_t *);
/*----- strbuf size related -----*/
static inline ssize_t strbuf_avail(const struct strbuf *sb) {
return sb->alloc ? sb->alloc - sb->len - 1 : 0;
}
int strbuf_grow(struct strbuf *buf, size_t);
static inline int strbuf_setlen(struct strbuf *sb, size_t len) {
if (!sb->alloc) {
int ret = strbuf_grow(sb, 0);
if (ret)
return ret;
}
assert(len < sb->alloc);
sb->len = len;
sb->buf[len] = '\0';
return 0;
}
/*----- add data in your buffer -----*/
int strbuf_addch(struct strbuf *sb, int c);
int strbuf_add(struct strbuf *buf, const void *, size_t);
static inline int strbuf_addstr(struct strbuf *sb, const char *s) {
return strbuf_add(sb, s, strlen(s));
}
int strbuf_addf(struct strbuf *sb, const char *fmt, ...) __printf(2, 3);
/* XXX: if read fails, any partial read is undone */
ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);
#endif /* __PERF_STRBUF_H */